Push-button type locks are known that provide the user with the ability to move the lock from the unlocked to the locked position simply by pushing a button without the need for a key. The key, however, is needed to move the push-button lock from the locked to the unlocked position.
For example, U.S. Pat. No. 4,009,599 is directed to a plunger lock and discloses a longitudinally movable shell within a housing. A locking wafer projects from the periphery of the shell and is received by a locking slot defined by the housing. The wafer is biased to project from the periphery of the shell. When the shell is pushed to the locked position and the wafer becomes aligned with the locking slot, the wafer snaps into the slot thus establishing the locked position. The wafer can then be withdrawn from the slot in response to proper manipulation of the key.
U.S. Pat. No. 1,369,308 is directed to a locking means for automobiles. The locking means includes a plunger provided with a pin tumbler lock which extends down inside of the plunger and has a cam at its lower end for engaging locking pawls. The locking pawls are formed in the shape of bell crank levers pivoted in the plunger, their inner arms being engaged by the cam and their outer arms being adapted to move out laterally to a locking position. Springs engage the inner arms of the locking pawls tending to move them laterally out of the slots.
Locks of different combinations, including push-button type locks, have been applied to steering wheel locks. Steering wheel locks typically hook to the steering wheel of an automobile and prevent rotation of the steering wheel. These locks generally have two rod-like portions that are extensible with respect to each other and include a locking mechanism for securing the two portions in an extended position. Key-operable locks used to secure the two portions of a wheel lock in locked position are, for example, disclosed in U.S. Pat. Nos. 5,255,544 and 5,174,138.
In accordance with the present invention, a lock is provided containing a housing having a push-button assembly that is slideably disposed within a cavity in the housing. The push-button assembly has an unlocked position and is retained within the housing while in this unlocked position by a lever included in the assembly that engages a first surface within the cavity to prevent axially movement of the push-button within the cavity.
Inserting the push-button assembly into the cavity moves the lever into engagement with a second surface within the cavity. The assembly is then in the locked position and is held in this position by the engagement of the lever with the second surface. Although the push-button assembly can be moved from the unlocked to the locked position by pushing it into the cavity, a key is required to turn a lock cylinder within the assembly to move the push-button assembly from locked position to the unlocked position.
The push-button assembly of the present invention is applied to a steering wheel lock and is disposed in a first cavity within the housing of the steering wheel lock. A first engagement member attached to the housing is provided for engaging a steering wheel. The housing also includes a second cavity intersecting the first cavity. A rod is slidingly disposed in the second cavity. The rod has a second engagement member attached thereto for engaging the steering wheel and a corresponding non-cylindrical shape to prevent rotation of the rod in the second cavity. The rod is capable of sliding axially within the second cavity to move the second engagement member into and out of engagement with the steering wheel.
In the locked position, at least a portion of the push-button assembly containing a fastening surface extends into the second cavity to engage at least two of a plurality of circumferential notches disposed along the rod. Thus, when the rod is positioned such that the second engagement member is in contact with the steering wheel and the push-button lock assembly is moved to the locked position, the steering wheel lock is secured.
The arrangement of this lock provides easier attachment of the lock to the steering wheel and increased security. The push-button lock of the present invention is less susceptible to being defeated by xe2x80x9crappingxe2x80x9d, that is overriding the spring forces of the locking mechanism by imparting a force such as by a hammer through the housing to the locking mechanism. In addition, the steering wheel lock is more resistant to forces applied to an end of the rod in an attempt to shear the members holding the two portions of the lock.